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    <title>Document</title>
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  <body>
    <script>
      String.prototype.firstAppear = function () {
        let obj = {};
        if (obj.children) {
        }
        len = this.length;
        for (let i = 0; i < len; i++) {
          // console.log(obj);
          console.log(this[i]);
          // console.log(obj[this[i]]);
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      let oneString = "jjisisdfj";
      let t = {};
      t["j"];
      // console.log(oneString[2]);

      let obj = { name: "赵杰", age: 20 };
      let objC = {};

      objC.name = obj.name;
      objC.age = obj.age;
      obj.name = "zj";
      console.log(objC);
      console.log(t);
      console.log(oneString.firstAppear());
    </script>
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